Transparency registering device for the stage of a visual image projector



Aug. 8. 1967 J s. WRIGHT 3,334,540

TRANSPARENCY REGI STERING DEVICE FOR THE STAGE OF A VISUAL IMAGE PROJECTOR Filed May 25, 1964 w /z 22 34 j d 3 INVENTOR.

BY Jaw/v i Mew/ r flux/n7:

United States Patent Ofitice 3,334,540 Patented Aug. 8, 1967 3,334,540 TRANSPARENCY REGISTERING DEVICE FOR THE STAGE OF A VISUAL IMAGE PROJECTOR John S. Wright, 627 E. Birch Ave., Milwaukee, Wis. 53217 Filed May 25, 1964, Ser. No. 369,971 7 Claims. (Cl. 88-24) This invention relates to a transparency registering device for the stage of a visual image projector.

The invention is of particular importance when transparencies are to be superimposed in the course of a lecture or otherwise so that the charts or images pictured thereon will be in full registry to enable the operator to project the total of all of such images onto a screen.

The stage is normally horizontal. The transparent imagebearing plastic sheets are very smooth. In the absence of some special equipment for registering the sheets and maintaining them in registry, it is easily possible for a previously deposited sheet or sheets to be displaced either in the course of the placement of a subsequent sheet or during a lecture with regard thereto. Accordingly, the present invention consists of a transparency positioning head, sometimes used as a part of an auxiliary stage, which may be placed on a conventional transparent projection stage and which has its sides generally open and unobstructed but includes a stop for engaging at least one end and sometimes portions of the sides of each successive sheet placed thereon. Thereby the newly placed transparency, and any associated sheets previously or subsequently placed will be fixed in absolute registry.

A weight preferably comprising a floating roller is used to hold the sheets flat by engaging their registering remote ends, this being supplemental to the fixed stop against which the remote end of the sheet abuts. Each successive sheet is pushed beneath the roller, which rotates as the sheet is moved toward the terminal stop. The roller holds the sheet down but without impeding its inward or outward movement. The fact that the roller floats enables it to rise to receive successive sheets superimposed on the sheet first inserted.

It is desired that the sheet itself be provided at the end opposite that which is engaged by the roller with a translucent area on which the lecturer may place notes which will be illuminated from below by the projection lamp and can easily be read by the lecturer without being projected onto the screen.

In the drawings:

FIG. 1 is a view in the invention.

FIG. 2 is an enlarged plan view of the device shown in FIG. 1, with the transparency omitted.

FIG. 3 is a view of the device shown in FIG. 2, partially in longitudinal section and partially in side elevation.

FIG. 4 is a fragmentary detail view in perspective showing a modified design.

The framing device is preferably in the nature of an auxiliary stage comprising a transparent table plate 6, which may conveniently be made of plexiglass or the like, and is supported by feet 8 at its corners. At the end remote from the operator, the auxiliary stage includes a head 10 with a downwardly opening generally cylindrical channel 12, the wall of which is slightly more than 180 in arcuate extent, and a rear wall 14 constituting a workpositioning surface. Floating in the inverted channel 12 is a roller 20 which serves as a weight to hold successive transparencies such as that shown at 22. Since the weight is a freely rotatable roller, it offers little resistance to insertion or removal of a sheet and it needs no manipulaperspective of equipment embodying tion, being cammed upwardly by the inserted sheet, which is stiff enough to perform this function. Removable end caps 16 and 18 are engaged frictionally in the channel 12 to confine the roller against axial displacement.

The dimensions of the transparent table plate 6 are preferably such that its width corresponds precisely with the width of the transparency 22. Thus when the transparency 22 has its rear end pushed beneath the roller 20 into engagement with the stop wall 14, it is positioned with great accuracy on the auxiliary stage. Any successive transparency superimposed on the first and similarly positioned will have all its display material thereon in full registry with the material on the first transparency. If desired, the head may be equipped with transparencyconfining side flanges as suggested at 16 in FIG. 4. Ordinarily, these have been found unnecessary if the lateral dimensions of the transparency match those of table plate 6.

It will be observed that there is no rigid anchorage of any kind. Any or all of the transparencies can be withdrawn immediately by simply pulling them forwardly away from the stop wall 14. The roller 20 rotates during the insertion and during the removal of a transparency.

In the construction shown in FIG. 4, the stop wall 140 is formed on the relatively heavy block portion 26 of the head 100. No auxiliary platform 6 is required, although one is shown. The weight of the block 26 will hold the head stationary even without any connection to the table plate. The side walls 16, if used at all, can be screwed to the end of the block 26 as exemplified by the side wall 100. The roller 200' may be identical with roller 20 except that, to exemplify another suitable arrangement, it is positioned by cranklike arms 28 pivoted at 30 to the block 26 and pivoted at 32 to the ends of the roller 200. The operation is the same as that above described.

The otherwise transparent table may, if desired, have a strip or strips of masking material 34 to frame the charts or maps or pictures on the several transparencies. In the exemplification of FIGS. 1 to 3, I have shown only one mask 34 which may conveniently be made of Mylar tape which has been aluminum coated. By way of example, and not by way of limitation, I have used a plexiglass table plate ten inches wide and ten and onehalf inches in length with an unobscured transparent portion eight by ten inches in size between the opaque framing area 34 and the roller-equipped head 10.

The transparency sheets 22 desirably have front end areas 36 opaqued by silk-screening pigment such as paint either on the top or lower surface of the transparent sheet. The opaque areas may be made to register with the opaquing tape 34 which frames the transparent area through which light reaches the transparency for projection of the image thereon. Material written in registry with the translucent area 36 will not be projected but will be readily legible. Assuming that the sheet 22 is made of plastic and the opaquing pigment is applied to its lower face, it is possible to write notes with a grease pencil upon the upper face of the plastic sheet above the opaqued area, and to wipe olf the writing when it is no longer required.

I claim:

1. A device for positioning transparencies on the stage of a projector, said device comprising a relatively fixed head having a stop surface so positioned as to be abutted by the end of the transparency, and a floating weight constituting means for holding a transparency in position after it has been engaged with said stop surface, said head having means for holding the floating weight in predetermined relation to said surface while accommodating vertical movement of said weight.

2. A device according to claim 1 in which said weight comprises a roller, the means for holding the roller comprising fixed guide surfaces having upright extent and spaced from each other and together being spaced forwardly from the stop surface of said head, the roller having portions rotatably confined and vertically reciprocable between the guide surfaces to accommodate floating vertical movement and rotation of the roller.

3. A device according to claim 1 in which said weight comprises a roller, the means for holding the rollercomprising an inverted channel having closures at its ends and below which the roller is exposed for contact with transparencies, the dimensions of the channel in cross section being sufiiciently in excess of the diameter of the roller to accommodate floating vertical movement of the roller.

4. A device according to claim 1 in which the member providing the stop surface constitutes a block having arms pivoted thereto and including portions in engagement with said weight, the weight comprising a roller rotatable on said portions, the arms constituting means for positioning the roller while accommodating yielding upward move ment of the roller in response to work inserted therefor rotation and for generally vertical movement between the lateral walls; 1

6. A device for positioning transparencies for projection and comprising a head having a stop surface adapted to be abutted by the end of a transparency positioned for projection, said head including an inverted channel, a roller confined in the channel and having its lower surface exposed to engage a transparency which is engaged with the stop surface in position for projection.

7. A transparency positioning device according to claim 6 in which the channel has end closures confining the roller against axial displacement, said channel having a cross section sufficiently in excess of the diameter of the roller to accommodate floating vertical movement of the roller.

References Cited UNITED STATES PATENTS 574,214 12/1896 Olmsted 8824 1 1,649,621 11/1927 Slocum 8824 2,672,787 3/1954 Schreiber et a1. 8824 2,944,461 7/ 1960 Howell et al 8824 3,039,350 6/ 1962 Gollhofer 8824 3,190,174 6/1965 Field 8824 JOHN M. HORAN, Primary Examiner.

NORTON ANSHER, Examiner.

H. H. FLANDERS, Assistant Examiner. 

1. A DEVICE FOR POSITIONING TRANSPARENCIES ON THE STAGE OF A PROJECTOR, SAID DEVICE COMPRISING A RELATIVELY FIXED HEAD HAVING A STOP SURFACE SO POSITIONED AS TO BE ABUTTED BY THE END OF THE TRANSPARENCY, AND A FLOATING WEIGHT CONSTITUTING MEANS FOR HOLDING A TRANSPARENCY IN POSITION AFTER IT HAS BEEN ENGAGED WITH SAID STOP SURFACE, SAID HEAD HAVING MEANS FOR HOLDING THE FLOATING WEIGHT IN PREDETERMINED RELATION TO SAID SURFACE WHILE ACCOMMODATING VERTICAL MOVEMENT OF SAID WEIGHT. 